Belt grinder



J. M EWAN BELT GRINDER June 2, 1953 5 Sheets-Sheet 1 Filed April 1, 1952 INVENTOR. .Awz: Mfw/w Juhe 2, 1953 J. MOEWAN 2,640,304

BELT GRINDER Filed April 1, 1952 3 Sheets-Sheet 2 INVENTOR. J4!!! Mfwmv June 2, 1953 McEwAN 2,640,304

BELT GRINDER I Filed April 1, 1952 3 Shee'ts-Sheet 5 INVEN TOR.

Y 71 mdm Patented June 2, 1953 UNITED STAT ES PAT ENT 2,640,304

BELT GRINDER;

James: McEwan, SamJose, Galif.

Application April 1,1952, No; 279,787

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invention: relates to belt grinders and more particularly to improvements tlireizeini which enable; ease of use. and adjustment:

The; principal object. at the invention is to. provide an; improved belt grinder construotioni in. which; tension. of' the" belt can be. relieved with-- out distlrcbing: any adjustment. Another ob loci: of the. invention is; to provide am improved. grinder whichv is constructed for operation. and? erorunmiof manufacture.

Gillie]: objects. advantages of the invena tion will; become apparent: from the; following description of certain preferred embodiments thereof, taken in connection with the accoml it drawings, in which:

1. is a. side elevational View oi the grinder;

Fig. 2 islaiv crticazl' secidonaliviem of the. grinder.

Fi 3 is; a, borizontala sectional: View" taken; in a plane indicated by the line 3-.--3 in Figure a Fig. 4; is: a sectional: view: taken a. plane dicated, by the: line 4-4; Eigtnze: 33..

Figs 5' is a. sectional view as indicated by the line: 5i--5r 4..

Fig. 6 isv a plan View; of; a, modified form of: the invention.

Referring to Eigures 1,. 2. 3,. the grinder includes: a base t0: carrying: a post bl: atztheupper end of which a. frames [2; is. adjustably clamped by bolt I15, The: frame t2 carries: at.

its: front end. a. boss: F13 which a shaft: W is.

journaled to support a drive pulley E6; The shaft. M: has a. conventional V-belt drive I! to a motor I8 suitably mounted on the post II. A grinding belt: 2:! is trained about; the drive pulley It and. an. idler pulley 22,..whose mounting is referred to hereinafter, The belt 2|. has. its upper stretch supported a work. table 23 adiustabIy clamped onthe main frame I12. at 24. A work opening above the table. 23 is provided in an upper housing member-26 which is; hinged at 2-! to a. lower housing member 28 which is secured on the frame [2. The housing; member 26' is adjustably clamped in position by a hand nut 29-. A door- 3lishinged at 32 to the. 110118;- ing member 26 to close its work' opening; as lustrated Figure 1'.

Formed integrally with the lower housing member 28 is an inlet housing 33 for a conventional blower 34 having its outlet directed into a bag 36. The blower 34 is also driven from the V-belt drive l1. Respective side doors 31 and 38 (Figure 1) are provided for the housing members 26-28 and housing 33, and are held in closed position by respective hand nuts 39.

The rear or idler pulley 22 (Figures 2 and 4) 2. is journaledl cm a stub shafit 4" which is secured: in an. upright poise 42 having a mount om a. 431 sen used; in: upright. ears.v 44 of a. base plate: 46.. A spring-4 is. disposed about the pin 43 between one arm of the yoke re and one I The; frame.- bracket: 51; is. secured; by suitable:

studs- 52 to.- the trame l2 The plate 4h has: a; pivotal: connection. provided; bya pivot 33 to: the bracket. 51, at. a. location below" and in: van-- tica'ls. alignment with; the axis of shaft 41,. for p ley- 22%, The plate: 43= also has respective arcuate slots: 54 concentric. with pivot. stud 53 and prosvid-ing for. adjustable; connection to the frame: brackets by means of studs- 56,, friction. washers: 5-1, and nuts 55. Each friction washer 51- is composed. of two. metal. washers with an inter-- posed. resilient washer 51d of rubber. or other similarmaterial. The. plate 46; (Figure 5): is provided with an apertured car 58; in which is journaled an adjusting rod 53 also threaded, in a. boss. a l at the frame bracket 51.. A. spring; 62: is interposed between the. boss 6t and. the; boss. 58 to. maintain the, adjusted positiom of the plate 4.6;. By turning hand knob 53, (Figure 3) on rod; 591 the. position. of, the plate 48; can. be. changed tosecure the desired pulley alignment.

Adjustable means. is provided to: place a doe sired tension on. the belt, 2| and to, enable release ofthe belt; 2|, fromthe idler pulley 22 with, out affecting; the tension adjustment: for. the. belt; E'or this purpose an adj usting, screw t6. (Figures. 3,, 4; and. 5.),v extends between the yoke, 42? and the pair. of upstanding ears. 6.? on the plate 45, the screw; 63 having threaded. engagement with a shaft 63. pivoted in the yoke. 42 and. passi'ng freely through. an apertured shaft. 69; extend ihg between the two ears 61. A spring H is compressed between the shaft 69 and the screw handle 12, urging the screw 66 to the right in Figures 3 and 5 and correspondingly urging the idler pulley 22 to maintain a desired belt tension. A stop nut 13 is provided on the screw 66 to engage a stub shaft 69 when no belt is on the pulleys.

It will be seen that by grasping the handle 48 the yoke 42 can be rocked counterclockwise as viewed in Figure to move the shaft 4! and the pulley 22 supported thereon out of engagement with the belt. This compresses the spring H but does not change its adjustment. Subsequently when the belt is properly aligned or when a new belt is in place, the tension adjustment is present without change.

In the modification of Figure 6 there is shown a pulley supporting and adjusting unit which can be placed at anydesired distance from a drive pulley where long grinding belts are employed. The unit shown in Figure 6 includes a frame plate 8| which is apertured at 82 for bolting to a work table, for example, and which includes a.

plate 48, a yoke 42, and an adjusting screw 66 identical in construction and mounting with those previously described in connection with Figures 1 through 5. The only difference from the former modification, other than the plate 8!, is in the adjustment for alignment of the pulley 22. A screw 83 is fixed in an ear 84 of plate 8| and passes through the apertured car 58. A hand nut 88 is threaded on the screw 83 for determining the adjusted position of the plate 46 and the pulley 22 on th frame plate 8|.

While I have shown and described certain preferred embodiments of the invention, it will be apparent that it is capable of further modification and. variation, so that its scope should be limited only by the proper scope of the claims appended hereto.

I claim:

1. In a belt grinder, a frame structure, a grinding belt, a drive pulley on said frame structure supporting on end of said belt, an idler pulley supporting the other end of said belt, a supportplate for said idler pulley, means mounting said support plate in a horizontal position on said frame structure for adjustment about a vertical axis, a yoke having a pivotal supporting connection with said plate and carrying a shaft supporting said idler pulley, the axes of said shaft and said pivotal connection being parallel, and adjusting screw having a threaded connection with said yoke and a slidable connection with said plate, a spring interposed between said plate and said screw and acting through said screw to urge said yoke in a direction to tension said belt, and a handle portion on said yoke for manual control thereof to move said idler pulley to and from engagement with said belt.

2. In a belt grinder, a frame structure, a grinding belt, a drive pulley on said frame structure supporting one end of said belt, an idler pulley supporting the other end of said belt, a support plat for said idler pulley, means mounting said support plate in a horizontal position on said frame structure for adjustment about a vertical axis intersecting said idler pulley, said mounting means also including a frictional connection between said plate and said frame structure, and an adjusting connection therebetween for effecting relative movement about said vertical axis, an operating member for said adjusting connection extending in a direction toward said drive pulley,

'4 a yoke having a pivotal supporting connection with said plate and carrying a shaft supporting said idler pulley, the axes of said shaft and said pivotal connection being parallel, an adjusting screw having a threaded connection with said yoke and a slidable connection with said plate, a spring interposed between said plate and said screw and acting through said screw to urge said yoke in a direction to tension said belt, and a handle portion on said yoke for manual control thereof to move said idler pulley to and from enagement with said belt.

3. In a belt grinder, a frame structure, a grinding belt, a drive pulley on said frame structure supporting one end of said belt, an idler pulley supporting the other end of said belt, a support plate for said idler pulley, means mounting said support plate in a horizontal position on said frame structure for adjustment about a vertical axis intersecting said idler pulley, said mounting means also including a frictiona1 connection between said plate and said frame structure, a yoke having a pivotal supporting connection with said plate and carrying a shaft supporting said idler pulley, the axes of said shaft and said pivotal connection being parallel, an adjusting screw having a threaded connection with said yoke and a slidable connection with said plate, a spring interposed between said plate and said screw and acting through said screw to urge said yoke in a direction to tension said belt, and a handle portion on said yoke for manual control thereof to move said idler pulley to and from'engagement with said belt.

4. In a belt grinder, belt supporting means including an idler pulley supporting the other end of said belt, a support plate for said idler pulley, means mounting said support plate in a horizontal position for adjustment about the vertical axis intersecting said pulley, a yoke having a pivotal supporting connection to said plate and carrying a shaft supporting said pulley, the axis of said shaft and said pivotal connection being parallel, an adjusting screw having a threaded connection with said yoke and slidably connected to said plate, a spring interposed between said plate and said screw and acting to urge said yoke in a direction to tension said belt, and a handle portion on said yoke for manual adjustment of said idler pulley to and from engagement with said belt.

JAMES MCEWAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,153,479 Beugler Sept. 14, 1915 1,821,624 Emmons Sept. 1, 1931 1,916,543 Welch July 4, 1933 2,055,351 Hormel Sept. 22, 1936 2,300,643 Bostwick et al Nov. 3, 1942 2,313,254 Mead Mar. 9, 1943 2,449,519 Sutton Sept. 14, 1948 2,489,811 Perkins Nov. 29, 1949 2,507,372 Emmons May 9, 1950 

